A characteristic of the human skin is the presence of hair of which the appearance and nature usually differ according to the area on the skin. Depending from various circumstances, hair on the scalp is commonly highly wanted, whereas hair at other area's of the skin is often unwanted for various reasons, including for example beauty reasons, reasons of convenience, hygienic and medical reasons. Historically a few major methods for removal of undesired skin hair have been developed, namely shaving, depilation (hair removal by means of a chemical hair degradation process) and epilation (hair removal by pulling out unwanted hair by a purely mechanical method). All these methods present advantages and drawbacks.
Shaving with any type of razor blade, typically used for removal of beard hair, is often not suitable for removal of hair at other area's such as armpits, pubis and legs, and it presents the danger of cuts which in turn can lead to infections of these wounds. Shaving with an electric razor avoids cuts but may leave a dry skin and sometimes may lead to mechanical skin irritation. Depilation is also widely applied but is often provoking a highly undesirable chemical irritation of the skin.
Epilation presents the advantage that together with the hair also the hair bulb (hair papilla) is removed. This results in an increased lasting effect of the epilation because it takes longer for the hair to grow and to become visible again.
Epilatory compositions, which term as used herein has the usual meaning of a composition used to achieve hair removal by primarily mechanical means; typically belong to one or more of the following conventional types: adhesive strips, hot wax, cold wax, and sugar wax. An epilatory composition contains or may even essentially consist of an epilatory mixture; the term epilatory mixture as meant herein means that portion—or, in case an epilatory composition contains several epilatory mixtures: those portions—of an epilatory composition that actually achieve the desired epilatory function.
Adhesive strips often suffer from the drawback that either all the unwanted hair is not properly removed because it is insufficiently sticking to the adhesive on the strip, or, when the adhesive properties of the adhesive are increased, the skin is damaged when the adhesive strip is removed from the skin.
Hot wax compositions are already in use for centuries. Typically they are based on rosin wax, paraffin wax and/or beeswax. The wax composition is warmed up to become molten, is applied to the skin and then allowed to cool, forming a solid layer in which the hair is caught. Accordingly, the caught hair is removed from the skin when the solid wax layer is pulled off of the skin. Precautions for the application of hot wax on the skin are necessary to avoid burns, and good skills are required to obtain satisfactory epilatory results without damaging the skin. Furthermore, residues of the wax on the skin have usually to be removed by means of a solvent or oil.
Cold wax compositions largely correspond to hot wax compositions but typically comprise further components that ensure a pliable structure of the wax layer on the skin which improves the ease and comfort of the epilatory treatment. Removal of wax residues from the skin usually requires treatment with a solvent or oil too.
Epilatory mixtures comprising at least one carbohydrate, such as sugar waxes, commonly classified, depending from the temperature at which they are applied to the skin, as warm sugar waxes or as cold sugar waxes, are also in use already for centuries. They are typically based on sucrose and/or fructose as the main adhesive components. Warm sugar waxes are somewhat more efficient to remove unwanted skin hair than cold sugar waxes, but they suffer from the typical drawbacks of warm waxes, such as causing possible skin burns when not properly applied. Accordingly, cold sugar waxes are often preferred for epilatory treatments.
Various sugar-based epilatory compositions have already been covered by several patent applications and patents.
FR 2267755 discloses an epilatory composition for cold application composed of a mixture of the carbohydrates sorbitol, glucose and sucrose which have been dissolved in water under heating at a temperature below the caramelisation temperature of the sugar, and that further comprises glycerine and proteins which provide a softening effect to the skin. The composition, comprising about 72% carbohydrates (% dry matter), presents good adhesion to the skin and hair, and does not form a rigid mass when applied to the skin.
FR 2798064 discloses an epilatory composition for cold application comprising at least one sugar such as sucrose, fructose, glucose, honey, sugar syrup, and an additive that enhances the adhesion of the sugar to the hair on the skin. Typical additives include hydrogenated colophane, silicon polymers, proteins, and carbohydrates from plant origin such as starch.
CA 2289879 discloses an epilatory composition for cold application comprising sucrose, corn syrup, corn starch, citric acid and water, which forms a pliable cold layer on the skin, enabling removal of the hair from the skin when the layer is pulled off.
HU 0402393 A1 (XP-002448216) discloses a depilation paste that contains fructose, glucose and water, and does not contain acid.
EP 1541117 A discloses cosmetic rinse-off compositions comprising inulin-type fructan. The inulin-type fructan can be used to completely substitute cationic polymeric conditioning agents in conventional cosmetic rinse-off compositions.
DE 10247696 discloses cosmetic or dermatological emulsions, containing a combination of (a) a saccharide-N-alkylurethane; and (b) one or more surfactants, optionally together with (c) further cosmetic and/or dermatological agents or auxiliaries.
An advantage provided by sugar waxes, particularly warm sugar waxes, is that by means of these waxes the removal of undesired hair is rather easy and efficient, and that their use seldom leads to chemical skin irritation. Furthermore, residues from sugar wax on the skin can easily be removed with water or water and soap. Accordingly, sugar-based epilatory compositions are gaining increasing interest.
Furthermore, over the last years there is a strong increase in the trend to remove undesired hair, largely for beauty reasons. Consequently, there is a high increase in epilatory treatments, in particular in the use of sugar-based epilatory waxes by professionals as well as by non-professional people.
Accordingly, there is a need for epilatory waxes which have a high functionality in hair removal yet do not suffer from the disadvantages of known sugar-based waxes such as the need for hot application to the skin. As a result thereof, there is an ongoing search for alternative and/or improved sugar-based epilatory compositions.